Method of making long pressed tubular glass structures



E. SCHWARZ Nov. 9, 1943.

METHOD OF MAKING LONG PRESSED TUBULAR GLASS STRUCTURES Original Filed Feb. 13, 1939 INVENTOR. EUGENE 5 CH 3 Sheets$heet l WA RZ ('6, m ATTORNFY Nov. 9, 1943. E, SCHWARZ 2,333,745

METHOD OF MAKING LONG PRESSED TUBULAR GLASS STRUCTURES Original Filed Feb. 13, 1939 3 Sheets-Sheet 2 g INVENTOR.

Eua ENE ScHwARz BY Mai (5. @34

ATTORNEY.

Nova 9, 1943. E. SCHWARZ 2,333,745

- METHOD OF MAKING LONG PRESSED TUBULAR GLASS STRUCTURES Original Filed Feb. 13, 1939 3 Sheets-Sheet 5 INVENTOR. EUGENE SCHWARZ ftww 616L644 ATTORNEY.

Patented Nov. 9, 1943 METHOD oF-MAKrNG LONG PRESSED Y GLASS STRUCTURES g Eugene, Scl wirara, Aleirandriian ind; .assignoi' tor The Mantle Lamp Company of merioa, Chicago, 111., a' corporation of Illinois 7 Qrigi-nal application February.13, 1939, Serial Nos; 1256*,046. Dividedand this applioation October 9; 1940,,881121'N05'360565 1 My invention relates to an improved process for making;v pressed? glassware'by which a care fully determined quantity of molten glass is placed in a mold and pressedwagainst the surface of the mold by the insertion of a. plunger part: way into one end of "the mold, said plungier being of such dimensions as to press: the

- glass in the mold against its" entirei'surfac'e,

andafter. the glass engaging the "mold. sun-'4 face has set, the still fluent central ortzraxial portion of the .glass between-"the. end of; the plunger and the other end'ofi the mold, is expelled and blown out from the moldedand set glass structure by gas under pressure; said z'gas being preferably introduced; through the; plunge er; said other end of :the mold: being open at the time; to" permit the eiipellingi operation .L-The process described mayvbe usedeffetively where it is desirable: to make-as integral structures; molded glass pedestals and; slender' oo'lumns for any purpose, for example,'tor"iuse assielectrio lamp standards, the result with suchlamp structures being th-atQ the hollow oolumns-1=- serve-es conductor passageways for 'contaihingwelectric conductors extending from within the ="base's, through the columns of the lamps to the sockets thereofp' My improved roducing anydesired conrormation I of: hollow glass structure,- corresporidmgtd thenrold con formation, so thatan-y desired ornamentation may be employed that will perm-it the: mold to be opened and the glass structure removedthere from; and at the same time: the entireglass structure'is unitary from end to'ends and'may with glass lam-ps or glasslamp standards; in clude 'in any' case, a hollow lbase, a: tubular" spin dle or standard, anda'thre'aded uppei" end portion to receive a fitting to support the lamp socket; v i i My process referred to: is operatit/eas "a resul tof the chilling or setting ot the 'exteri'oi portion of the glass in the mold? resultingvirrom contact between the glass and the mold due to thepressing of the glass into the mold: hy' thdplu-nger. At the same time; although the exterior portion of the glass structure has setsiifliciently to pos sess Considerable stability, the central axial tion of'the glass structure in the mold is still the gas admitted axially under pressure against the glass infthe mold, as a result-oil whieh the central axial portion of the glass! thatisk fluent, is expelledor blown from" the remaining? portion of the glass structure, leavirigthe glasjs struomethod has the: advantage: of

, pro s ture witha central longitudinal'passageway of substantial; diameter extending fromend to' end oi the glass structure. Atthe same time, the gas under pressure in-m-an-y oases operates duringthe: expelling operation to more; intimately press theexterior portion of the glass structure: against the mold surface, dependingupon the: instant got admitting the: gas under tpressure tOi-th6= mo-1d. The, time of admitting the gas under pressure ihtoythe' mold; is determined by thethickness of glass wall Whichpit is desired for the finished, glassstructure to have, as well as'bythe melting temperature of the glass, the temperature ofthe: mold, the time required for theparticular glass to set,E and the particular kin-dot, glass :used in 2111371 case, asset result of which it is impossible: to stategenerally how long the glass should be; incontact Withthe mold before the gas pressure'is applied. It will also; be'understoodythatl the size or the glass article to be made in the-mold has much i to do with the timed chilling or setting before the: gas under pressure is supplied" to the mold; 'inasom'e caseswher'e a'i relatively'large glass article is desired to have: relatively #thin walls, the gas under pressure is applied promptly, after the pressing operation, whereas with the same glass article, if it is desired to have a, relatively thick wall; the chilling orisetting operation is permitted to' proceed foracorrespondihg length of time, before atdmit'tingthe gas under pressure to'the'nioldx 1 it This is 3a divisional application ofmy .copendingapplioation Serial? No; 256,046; filed Feb: ru-ary 13;"1939ynow PatentlNoi 2,274,096; issued February 2%;1942; 1 I i My invention herein relates tothe' process "described. The above and" otherobj'ects of my in= vention will more fully appear by reference to the accompan ing" drawin s illustrating a preferriedembodimerifthereof, v Fig. l is; a vertical, "cen ral; sectional View through a mold QFig'. 2' is a vertical, central," sectional riew through apart of the structure; taken along the line 2 -2 in Fig. 1,,

Figs, 3,. 4 and 5' are diagrammatic sectional views illustrating difierent steps of my process;

, Fig.3 showing a mold with a charge of; molten glassideposited therein, Fig, 4 illustrating the effect of the; plunger irr foroing the glass against the;*simfacesuof the mold, and? Fig. '5 illustrating the effect of -thdgas: under pressure in ejecting the central axial portion of the molded glass structure,

Fig. 6 shows in front elevation, a glass lamp stand having a straight column, produced by my process, and

Fig. 7 shows in front elevation, a glass lamp stand having a curved column, produced by my process.

Similar numerals refer to similar parts throughout the several views.

In Fig. 1, I show at ID a mold for'producing glass lamp standards of the kind referred to, in

which the base, the spindle or' standard .of the lamp and the upper end po'rtion'of the standard for mounting an electric socket, constitute an integral structure as illustrated. at l The mold. I is a split mold hinged together at l2 and i3 and provided with tapered locking pins l4 and" I5 forholding the mold in closed condition during the molding of the glass structure. The lower end of the mold is mounted on a base l6 and centeredthere'onbyafiange Ilia-carried by the base and engagingthe lower end of the mold to not only'center the mold on the base but also to lock the mold thereon against movement during v pressure to the mold when and to the extent desired. While gas of different kinds may be employed, as desired, I find it convenient touse air under pressure, since it is quite effective in removing the central axial portion of the molded glass structure that is still fluent; without detrimental eifect of any kind. The plunger 22, in its lowermost position, extends into the mold sufficiently to bring its lower end near the upper end of the spindle portion of the mold. The recess l8 usually is of suflicient capacity to accommodate any of the expelled or blown out 7. I glass due to'the admission of gas under pressure i 1 to the mold,.but 'in 'the event of a large quantity of glass being removed from the molded glass structure by the expelling operation, a relief openingbr openings 18a are provided from the recess 'l8-'throughthe base [6.

ported'underthe base .l6 by supporting guides 20 for horizontal movement, the lower portion of the plunger 11 "being slotted so that said plunger spans said cam plate as shown in Fig. 2. The camplate I9 is provided with a cam slot l 9a containing aroller Ila mounted on'a rod 2| extending through the lower end portion of the plunger I1, .so that movement horizontally-of the cam plate [9 movesthe plunger I! .either to its upper position closing the lowerend of. the mold ill, or I to'its lower position with'itsupper en'dsubstantially inthe lower surface oftherecess l8, as desired.

Theupper end of the mold- I0 'is' provided with a cover plate Illa, through which an upper plunger 22 may move vertically with a sliding fit, said plunger being carried by the ram. of .a suitable press, not shown. The plunger, 22' where it enters the mold l0 isof'the general conformation of the mold but of sufficientlysmaller'dimensions to leave a glass wall around the surface of the mold of a desired thickness.- The plunger 22 is provided with an:axia1'bore 22a extendingnearly to the lower end of said plunger; from which point small diameter bores 2% connect the bore 22a with the lower end of the plunger through which the bores 22bv open. Each bore 22b should be of small enough diameterto prevent the fluent glass from flowing into its lower end and setting therein. .The number of said bores 22b. employed, determines the rapidity with which a required quantity of ejecting gas can be delivered from the plunger 22 for any particular gas pressure employed. The upper portion of the plunger 22 is provided with a horizontal bore'22c'communicating with the bore 22aand connected atits outer end with a suitable stopcock 23 which in turn is" connectedby a'fiexib'le hosefll with a: source of'gas under pressure, not shown. The

stop cook 23 provides for admitting gas under end of the mold 210. -Wherethe glass structure, has a slender'spindle of the type illustrated,.-I i find-it generally :advisable; to open the cook 23 In carrying out myinvention, the plunger 22 is first raised sufficiently to clear the cover plate 10a ofthe mold, and'a charge ofglass (1118' placed in the mold as illustrated in Fig- 3, care being taken'that the charge shall be sufficient to completely fill the mold when the. plunger 22, I

is. forced downwardly into the mold. At thistime the lower plunger I1 is preferably held-in its uppermost position by the cam plate I9 to close the lower .end. of the mold. The plunger 22 is v then forced downwardly with the stopcock 23 inclosed condition; untiltheplunger occupies the position shown in Fig. 4, .further downward movement of the plunger being prevented bythe v engagement. of a shoulder formed on it with-the I cover plate Illa, for which condition of the parts,

the glass lluin the mold I0 is forcibly pressed against the surfaceof the mold; '1 During 1 the pressing. operation: the .plunger, l 1 preferably re v mains inlts uppermost position, closing the lower atzsubstantially the .time the plunger reaches its lowermostzpositiony; the lower; plunger. I'l. should have :been moved to its lowermost position .bythe cam; plate I9, at-' any time that the cook :23 is opened; ;Where the cross-section v0f the spindle of the glass structure is relatively large;-:or, a relatively thick tubular wall is desired,;-aicorre-' spondingintervalis allowedin which the tubular wall. may: set, before opening the cook 23; in"

still other cases, and particularly where spindle structures of small cross-section are involved,.I

find that'the cook 23 may be opened before the plunger 22-has reached its lowermost. position.

Bearing in; mind that the'central axial. portion of..theglass-in the, mold is still in fluent condition, the gas under pressure admitted into the' mold throughthe lower end of the-plunger 22,

forces the central axial portion of the glass down-.

wardly from the mold into the recess l8, where it collects. as indicatedv at lib for removal when the molded glass; structure is. removed from." the mold. During the. expelling or blowing; opera-, tion, thejexpelled. glassfollows to some .degree the contour of the moldas illustratedat lie. be,-

cause of the. glass being thicker at such points and therefore having a" larger cross-section of" fluent glass ,than at other points in the mold.

The result. as shown in Fig. 5,-is a passageway entirely through the glass1structure,-,- which 15 Y afittifig or metai or tthermatenarror the useof thef, lower plunge azesegrz is in Figi l' i's preierably proyided with threads-to similarly thread the glass structure," to r'eceiv p 1 ing a lamp socketetr'tne la -p standard QIri 'making'ismatl slenderj tubul' 'r' 'glass truc- -tures of 'the class reierred t l iarn ableto pro- 1 dude such integral 's'tructure'shaving' a length-of.

18 inches or more; and an external diametery of about /3 inch," and by the lilowing operationpl am able tofproduce' ai' passageway throu'ghthe: i

e "stl iltu l 'bf :abbut inchFvvhieI'iare-irOm Z M It will be observed that by my'i'rive'ntion be cheaply produced: 7 Where the lower of the i cross-section asillustrated, I flnd in some that the use of th" lower plungerll isiio ne'c essary, because of the slight chilling or setting effeet of thejglass at the i ow'er'enu oPthdmOld when} it; is forced into en agement therewith? by the plunger-22; F molded glass which is; slightly chilled-or setiat the lower: ofthe mold, is notes ffi'c ntly fluent to new from the mold' under hattibii of h the plunger 22", mayreadily: be

truct l tehythe e fi md e described; "It wiilfbefundrstood th tmy invenj tion is ailsoietprilicabl toglas" diameter than those" illustij forced "from the remainingglass supplying of'gas under pressu in many cases necessary fto the mold during-'thep 'es'sing o r be understood t1'iat ;the 'proces p c b hat dem particularly to ome hollow by ordinary pres ationsi.

While,fhayeilhistrated "the tubular spindle portion of glass articles made bymy described process as straight, it will be understood that said spindle portions may also be curved or of any desired form that can be made in molds by a plfissing operation or by pressing and blowing'operations, and that in any such case the central longitudinal portion of the spindles may be expelled passageway connects the hollow in the base, with I the upper'end of the lamp stand. In Fig. '7, I show a similar lamp stand lid, having acurved column, made in the same manner as the lamp stand shown in Fig. 6, which alsohas a central 7 passageway extending longitudinally through it from the hollow in its base to the upper end of the lamp stand, and made in the same manner as the passageway through the column of the lamp stand shown in Fig, 6. t

While I'have shown my invention in the par ticular embodiment above described, I do not limit myself to the particular construction, or stepsof treatment illustrated and. described, as I may employ equivalents thereofwithout departing from the scope of the appended claims. What I claim is:

l. The process of molding elongated tubular glassiarticles ihaving' enlarged integral axially- Tindfibases?toformla continuousextending entirely through which the -mtegrar base is formed cirigfltl-ie glass while still to saidj 'niold'f by mechanical ppe'r and; the temperature the latter' 'wliere it comes in I an {or tliidnioldfintroaxiallyftl'lldllgh said Jeans substantially sim'ul- V rcing,- "expellihg the fluent 0 of aid ch 3 glthiough Salididis r itting the retained and'cdiiimn 'or theartifclef 3. "The process of molding elongated tubular glass articles having enlarged integral axiallypierced supporting bases to form a continuous- Walled passageway extending'entirely through the article, said process including placing a charge of fluent glass in theupper end of an open-ended mold having a cavity conforming in shape to the outside of the article and having a discharge opening atits lower end, the part of the mold in I which the integral base is formed being uppermost, forcing the glass while still fluent downward into said mold cavity by mechanical means entering its upper end, the temperatureof the mold being sufiiciently lower than that of the charge to'chill the latter where it comes in close contact with the wall of the mold, applying fluid medium under pressure against a top surface of said charge to move said charge downwardly in the mold cavity, and expelling the fluent interior 1 portion of said charge through said discharge 1535 opening by said fluid medium.

4. The process of molding elongated tubular glassarticles having enlarged integral axiallypierced supportingbases to form a continuous- 1 of fluent glass in the upper end of an open-ended mold having a cavity conforming in shape to the outside of the'article, the part of the mold in which the integral base is formed being upper- 75 most, forcing the glass downward while still flicienj tly lower-than that of 4 fluent into said mold cavity by mechanical means entering the upper end thereof while-maintaining the lower endof said mold cavity closed,-the temperature'of the moldbeing suiiiclentlylower than that of the .charge to chill the: latter where it comes in close contactjwith the wall of themold, opening the lower end of the mold'cavity andintroducing a fluid medium ,under pressure against a top surface of, said charge-andexpelling the fluentvinterior portion of saidcharge from the lowerend ofthe .jmold. cavity by said fluid medium, said mechanical glass forcing and fluid introducing and expelling stepsbeing, carried through as a: substantially continuous operation.

' ,5, The process of making press-molded glass stands-,for, electric lamps having slender tubular columns including integraliattachment threads at their upper ends and enlarged; integral hollow supporting basesf having vertical side walls and horizontal top walls spaced; above the bottoms of the lamp stands and-adjacent the-lower ends of the column portions thereof and including integral supporting ifeet said process including pressing most by a plunger having: the 'conformation of the finished hollow portion in the baseof-thelamp v almoltenglass chargefrom above'vinto the base end of a mold cavity disposed base endfupperv stand, saidI moldjca'vity having the conformation of the external surface of the finished lamp stand.

and having a discharge opening at itslower end, applying pneumatic pressure downward, against the adjacent'top surface of the'charge "to blow fromthe column of "the lampstand itsicentral and still fluent portion; saidpres'singand blowing forming a substantially vcontinuous 1 operation, on the charge,and expeliingsaid central ii t'portion through-said discharge opening.

,6; The process of making a molded g1 havinga tubular vertical column with an enlarged upper end portion and having atits lower end an r integralsupporting base. extending. from the axis ass articletime column to afiord stabl'su'pport ,for the article, which process includes placing' a m'olten glass charge in a mold cavity having the 'conformationwof theentire; article including its"en;- larged upper-end portionand its :base portion and, Q having 8' discharge, opening at its lower end,1 ap -.r plying'to saidrocharge-.a?pres 11re;;to;fi11,theggsaid- I enlarged portionand the, said base portion of the a mold :cavity anditdmake contact between the charge and the entire surface of -the,mold'icavity.z then as, a substantially continuing operation applying pneumatic pressure against 'the end s face of-thecharge-in; the top of .the'mold and exit-1;

pelling; through said discharge opening the still art c e;

*7. In the process of making amolded glass electriolamp standard and the like having apas sageway extending entirely through it-axially and opening through both ends thereofand having a column and an integral supi'm'rting base] extend I ing laterally. to afford stable support for said standard, wherein a glasscharge is molded in a mold cavity having the conformation of the er I ticleincluding itsbase portion and having a dis charge opening at its lower end and the outer por-' tion only of. said charge has been permitted to solidify, the steps ,wl'iichinclucie applying pneue matic pressure against thetenda surface of the charge in the top er the mold cavity and expelling through said discharge opening the still .fiuent' axialportion'oif. the charge in the form'of 'a bubble projectingffromland connected .with the end of the articlefthen jreinoving the. article from the s mold'with'its supporting .base' completed as an integral part ofthe finished article, and then 'r'fe moving the bubble to complete the glass article.

SCHWARZ. v 

